Hi,

This is a common problem that can be caused by various factors, including operating system limits and the configuration of wkhtmltopdf for odoo.

Here are a few things you may try to resolve the issue:

1. In Odoo, try reducing the number of records per page, or using a more efficient query. This will decrease the amount of data being loaded into memory and may help reduce the number of open files.

2. Use a different PDF generation tool:

   • If increasing the number of open files or optimizing Odoo settings does not work, you could try using a different tool to generate the PDF file. There are several options available, such as PDFKit, WeasyPrint, and FPDF.

3. Contact your Odoo support.

I hope this helps

Regards